import React from 'react'

let timer = null
class TestThisXXX extends React.Component {
  constructor(props) {
    super(props)
    this.a = 'Jonny'
    console.log('this.a', this.a)
  }


  componentDidMount() {
    timer = setTimeout(() => {
      this.a = 'Micheal'
      console.log('this.a', this.a)
    }, 3000)
  }

  componentWillUnmount() {
    clearTimeout(timer)
  }

  render() {
    return (
      <div>{ this.a }</div>
    )
  }
}

export default TestThisXXX